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Main Forum => General Discussion => Topic started by: LynnWM1894 on September 11, 2021, 01:06:12 pm

Title: AC and heat
Post by: LynnWM1894 on September 11, 2021, 01:06:12 pm
I have a 2020 2552 that I have only driven to storage, house, and to the dealers so everything is new to me.  Yesterday I turned both ACs on and left for about 35 minutes.  When I returned the furnace was blasting along with the two ACs.  What did I do wrong?  I have had several motorhomes over the years but this stumps me.

Does anyone have any idea of what I did so that I don't do this again?

Thanks for your help.
Title: Re: AC and heat
Post by: mikeh on September 11, 2021, 03:14:45 pm
Lynn,

I'll watch this topic with interest and hopefully learn something.  I wouldn't think this combination should normally be able to occur.

On my 2019 2552, with 50-amp service and two A/C's, each of the two thermostats can select either Fan, A/C, Furnace, or Heat Pump/Strip.  If you had A/C selected on both the front and rear thermostats, and the A/Cs operating, I see no way for the furnace to properly be activated.

I think that I would try to replicate this situation to see under what circumstances you can get it to reoccur-----with the front TT on A/C?, with the rear TT on A/C?, only when both TTs are on A/C?  Does the furnace activate normally from each TT on it's own?  There could be a wiring issue in the thermostat circuit, I suppose.  While anything is possible, I can't think of a more likely fault.

Mike
Title: Re: AC and heat
Post by: donc13 on September 11, 2021, 09:23:37 pm
I don't know if they still do this or not... In my 2015 (only 1 thermostat and 1 a/c) the wiring from the thermostat (3 wires for mine) run up to the a/c unit.  Nothing from the thermostat goes to the furnace, the 12v "brain" of the air conditioner not only controls the air conditioner, but also turns the furnace on/off.

IF the 2920 models are wired the same, then one of the A/C units (most likely the "front" a/c (which works with just 30amp service or generator) is miss-wired on the furnace wires or the controller board is defective.

Definitely sounds like time to get a warranty repair on your PC before it runs out!  (or has it run out?).